1. Field
The described technology relates to systems and methods of updating graphical information representing a polygonal data object.
2. Description of the Related Technology
Polygonal model data is created with, for example, a 3-D CAD software tool by, for example, a designer. The polygonal model or polygonal mesh includes discrete data points describing one or more surfaces or objects. Polygonal models are convenient for design work at least because they define the surface or object with a degree of detail convenient for the designer to work with. The shape of the surface or object is defined by the data points, and the surface between the data points is perceived, but is not necessarily represented in the data. This allows for the CAD system to function quicker because of a significantly reduced data set representing the surface or object, while providing the designer enough detail to manipulate to achieve a desired design.
The polygonal data may be edited by a designer according to the designer's purposes. For example, the designer may add features to the object represented by the polygonal data using mesh operations. In addition, to create smooth, natural looking objects, a smoothing algorithm may be used to modify the polygonal data. For example, a Catmull-Clark algorithm or a Loop subdivision algorithm may be performed on the polygonal data. The smoothing algorithm modifies the polygonal data by, for example, adding vertices and repositioning existing vertices. Thus, the smoothing algorithm generates a modified object.
Typically the polygonal data is shown on a display with the smoothed object. As the designer edits the polygonal data in the design process, the smoothed object is updated to show the result of the designers edit. The polygonal data object includes a number of geometries, such as vertices, edges, and faces. In some applications, if the number of geometries is large enough, when the polygonal data is edited, the process of graphically representing the smoothed object can overload system resources such that the designer has to wait an undesirably long time for the graphical updating process to finish. Such waiting is wasteful and interrupts the workflow of the designer, and accordingly lowers productivity.